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[[ Genus Percina ]]
There are 41 described species in the genus Percina (Near & Benard 2004; Nelson et al. 2004), the secondmost species rich of 10 genera currently recognized in the family Percidae (Song et al. 1998). Of the 41 named species, 13 are known from the Mobile Basin of Alabama, Georgia, Mississippi and Tennessee, and six are endemic. Our description of three new species brings the total number of described species in the Mobile Basin to 16, nine of which are endemic to the Mobile Basin, representing the highest level of endemism in the genus Percina within any drainage of North America.
The first of the three new species to be recognized as taxonomically distinct, Percina smithvanizi , Muscadine Darter, was discovered during a survey of fishes in the Tallapoosa River drainage of Alabama and Georgia (Williams 1965). In the late 1960’s, P. kusha , Bridled Darter, was discovered in headwaters of the Coosa River in Georgia and Tennessee (Stiles & Etnier 1971). Percina sipsi , Bankhead Darter, endemic to a small area in the Sipsey Fork watershed of the Black Warrior River drainage in north-central Alabama, went undetected until 1971 (Dycus & Howell 1974). Following discovery of these species, their existence, distribution, and presumed placement within the subgenus Alvordius became general knowledge among darter systematists. However, their recognition as valid species or subspecies was not consistent. Knowledge of the existence of these taxa has led to numerous published references to them as bridled or muscadine darters and Percina sp., Percina (Alvordius) sp., or Percina sp. cf. macrocephala , in ichthyological and conservation literature during the past four decades (Page & Burr 1991; Etnier & Starnes 1994; Boschung & Mayden 2004). Most publications referring to the three Percina species described herein included river drainage distribution data which facilitated association of citations with each of the three new species.
Prior phylogenetic studies of the genus Percina included samples of two of the three taxa described herein. Page & Whitt (1973a, b) included P. kusha and Near (2002) included P. smithvanizi in molecular studies. Page & Whitt (1973a) used isozyme variation of lactate dehydrogenase (Ldh), malate dehydrogenase (Mdh), and tetrazolium oxidase (To) loci to assess the relationships within the Etheostomatini, and Page and Whitt (1973b) used isozyme variation of Ldh to assess the monophyly of Percina . None of these loci were variable enough to infer relationships within subgenera of Percina , or to unequivocally determine sister relationship of P. kusha . Near (2002) postulated P. smithvanizi as the sister to P. palmaris based on mitochondrial cytochrome b gene sequence, although support for this clade was weak and other possible relationships varied depending on method of analysis.